Regenerative furnace



Dec. 11, 1928.

W. MILLWARD REGENERATIVE FURNACE Filed July 5, 1923 than. H, ldfi.

l i T E S T I WILLIAM MILLWARD, F PITTSEQRGE, PENNSYLVANIA.

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Application filed July 5, 1923. Serial No. 6459,501.

Heretofore, it has been usual'in furnace operations to introduce the gas at such velocities as may be established by the pressure on the producer, the extent to which the gas inlet valve is opened, and the pull of the stack. The amount of air supplied and the velocity thereof depends on the regulation of the air inlet valve, the temperature of the regenerator, and the pull of the stack. The opera- 0 tion was regarded a success if the air over,-

took andburned the gas before it reached the end of the furnace. Otherwise stated, little or no importance was attached to securing proper admixture of the air and gases as a condition precedent to ultimate combustion.

The principal object of my invention is to provide for sharp combustion, thereby shortening the furnace operation and increasing the eflicieney of the furnace. I attain this result, without regard to the source and character of the gas, by a systematized boosting and dilution of the gas with appropriate supplies of air, and by effecting the mixing of the air and gas in stages. In short, the essence of my invention resides in eflecting primary and secondary mixing of the air and gas, and to some extent it depends on an unobstructed or free passage for the air rising from the ac regenerator system.

With such and other objects in view, the nature, characteristic features and scope of the invention will more readily be understood from the following description taken in con- 35 nection with the accompanying drawings,

forming a part hereof, wherein Fi ure 1 is a sectional view of an open heart 1 furnace of the regenerative type, showing principally the gas and air uptakes My from the slag pockets and the means for effecting stage mixing and for boosting the velocity.

Fig. 2 is a transverse section.

Referring to the drawings, it will be manifest to those skilledin the art that fuel for the furnace 1 is essentially supplied, as is usual, from the slag pockets of the regenerators, the gas rising in the uptake 2 and the air rising in the uptake 3. The gas uptake 2 .is provided with a gooseneck terminal 4, the nose or delivery portion of which is equipped with a water jacket 5. A blast nozzle 6 projects into the gooseneck and supplies air under proper control to dilute the gas 66 and to boost the velocity thereof. the nozzle is so disposed with relation to the outlet of the gooseneck, that the upper or horizontal arm of the latter constitutes a primary mixing chamber (2, wherein air is mixed with gas coming from the checkerwork. The gooseneck 4: does not overhang or extend into the air uptake 3, but discharges its mixture across a gap into a secondary mixing chamber 6, wherein further mixing takes place with the air rising untrammeled in the free and unobstructed air passage 3. As shown in Fig. 2, the delivery or outlet portion of the gooseneck and the element 77, forming the mixin chamber 5, are preferably, but not essentially,

oval in cross-section. The merit ofthe oval shape is that it ensures a comparatively wide and'shallow flame- Whatever cross-section is employed it is important that the blast nozzle, gooseneck terminal, and secondary mixing chamber be relatively centered, and that the intake of the secondary mixing chamber be substantially flared as at 8.

While I have merely illustrated and referred to essentials of the invention, it will be understood that atmospheric air is supplied to the gooseneck in the direction of the flow of gas and at any desired pressure and that the gas is thus boosted to that velocity necessary to induce the air in the air uptake into the secondary mixing chamber. The velocity may be governed by the size of the nozzle. The point of desired combustion with a given gas depends upon the degree to which the gas s diluted with oxygen in the primary mixmg chamber, the prompt admixture with this mixture of the air rising in the air uptake,

and of course the temperature of all. Combustion may be delayed somewhat by drawing Waste gases from the outgoing regenerator, mixed with atmospheric air to cool them, into the blower so that the air blast will contain less oxygen, and the amount of oxygen may also be regulated by the temperature of the air blast. Manifest'ly, the flame in the fur nace may be made as short or as long as desired by the speed of the blower and by the use of the usual regulating valves for gas and air inlets. If desired, as in heating furnaces, to efie'ct complete combustion directly the fuel enters the hearth, the flame is so shortened as to be practically invisible, but for melting purposes this of course is not practical as the melting is best accomplished by the cutting action of the flame and the letter must have body to cut the metal. The rate of transmission of heat from the gas to the metal by convection increases with the velocity of the as flame. I p

aving described my invention, I claim 1. Means forefl'ecting sharp combustion in furnaces of the regenerative type, comprising the combination with the gas and air uptakes, of aprimary mixin chamber in the outlet end of the gas u ta e, means for supplying air thereto for oosting and diluting purposes, and a secondary mixing chamber in line with the first and spaced therefrom by the air uptake. 2. Means for efiecting sharp combustion in furnaces of the regenerative type, comprising the combination of a as uptake having an outlet arm, a mixing 0 amber in said outlet memes obstructed air uptake, a gooseneck terminal for the gas uptake and stopping short of the air uptake and constituting a primary mi);- ing chamber, means for supplying it with air under pressure, a secondary mixing chamber centered relatively to the first and to said means, and a system of control.

In testimony whereof I aflix my signature.

' WILLIAM MILLWARD. 

